This invention relates generally to wind turbines, and more particularly to the control of the temperature inside a hub of a rotor of a wind energy turbine.
Large modem type energy turbines include rotors having hubs which include several components such as a rotor blade actuator (pitch) drive which produce energy losses in the form of heat that increases the temperature inside the hub. In some types of wind energy turbines, the temperature inside the hub increases due to heat flow from components of the nacelle located close to the hub of the rotor. Due to the shaft of the rotor extending from the hub into the nacelle there is a relatively large opening between the hub and the nacelle where warm air from inside the nacelle can easily propagate into the hub. At higher ambient temperatures the above-identified two effects can lead to temperature levels inside the hub which are higher than the upper temperature limits tolerable for the components arranged in the hub.